A South Sudan opposition official says rebel forces have reclaimed their stronghold of Pagak, a week after being pushed out of the town by government forces.

Col. Lam Paul Gabriel, deputy spokesman for the opposition IO, told the Associated Press that the government troops were pushed out of Pagak, in northeastern South Sudan, over the weekend. He said many of the government troops crossed into Ethiopia where thousands of South Sudanese are seeking refuge from the ongoing clashes.

Since fighting erupted in South Sudan almost four years ago, Pagak has been headquarters of the opposition, led by former Vice President Riek Machar, currently in exile in South Africa.

Army spokesman Lul Ruai Koang wouldn't confirm that the rebels recaptured Pagak but said government forces were in Maiwuk nearby.